This article examines citizen scoring in China's Social Credit Systems (SCSs). Focusing on 50 municipal cases that potentially cover 210 million population, we analyze how state actors quantify social and economic life into measurable and comparable metrics and discuss the implications of SCSs through the lens of social quantification. Our results illustrate that the SCSs are envisioned and designed as social quantification practices including two facets: a normative apparatus encouraging “good” citizens and social morality, and a regulative apparatus disciplining “deviant” behaviors and enforcing social management. We argue that the SCSs illustrate the significant shift in which state actors increasingly become data processors whereas citizens are reconfigured as datafied subjects that can be measured, compared, and governed. We suggest that the SCSs function as infrastructures of social quantification for enforcing social management, constructing differences, and nudging people towards desired behaviors defined by the state.